Computing Volume Bounds of Inclusions by EIT Measurements

The size estimates approach for Electrical Impedance Tomography (EIT) allows for estimating the size (area or volume) of an unknown inclusion in an electrical conductor by means of one pair of boundary measurements of voltage and current. In this paper we show by numerical simulations how to obtain such bounds for practical application of the method. The computations are carried out both in a 2D and a 3D setting.Comment: 20 pages with figure

Characterization of ellipses as uniformly dense sets with respect to a family of convex bodies

Let K \subset R^N be a convex body containing the origin. A measurable set G \subset R^N with positive Lebesgue measure is said to be uniformly K-dense if, for any fixed r > 0, the measure of G \cap (x + rK) is constant when x varies on the boundary of G (here, x + rK denotes a translation of a dilation of K). We first prove that G must always be strictly convex and at least C1,1-regular; also, if K is centrally symmetric, K must be strictly convex, C1,1-regular and such that K = G - G up to homotheties; this implies in turn that G must be C2,1- regular. Then for N = 2, we prove that G is uniformly K-dense if and only if K and G are homothetic to the same ellipse. This result was already proven by Amar, Berrone and Gianni in [3]. However, our proof removes their regularity assumptions on K and G and, more importantly, it is susceptible to be generalized to higher dimension since, by the use of Minkowski's inequality and an affine inequality, avoids the delicate computations of the higher-order terms in the Taylor expansion near r = 0 for the measure of G\cap(x+rK) (needed in [3])

[A cohort study on mortality and morbidity in the area of Taranto, Southern Italy].

Introduction: the area of Taranto has been investigated in several environmental and epidemiological studies due to the presence of many industrial plants and shipyards. Results from many studies showed excesses of mortality and cancer incidence for the entire city of Taranto, but there are no studies for different geographical areas of the city that take into account the important confounding effect of socioeconomic position. Objective: to assess mortality and hospitalization rates of residents in Taranto, Statte and Massafra through a cohort study, with a particular focus on residents in the districts closest to the industrial complex, taking into account the socioeconomic position. Methods: a cohort of residents during the period 1998-2010 was enrolled. Individual follow-up for assessment of vital status at 31.01.2010 was performed using municipality data. The census-tract socioeconomic position level and the district of residence were assigned to each participant, on the basis of the geocoded addresses at the beginning of the follow-up. Standardized cause specific mortality/morbidity rates, adjusted for age, were calculated by gender and districts of residence. Mortality and morbidity Hazard Ratios (HR, CI95%) were calculated by districts and socioeconomic position using Cox models. All models were adjusted for age and calendar period, and were done separately for men and women. Results: 321.356 people were enrolled in the cohort (48.9% males). Mortality/morbidity risks for natural cause, cancers, cardiovascular and respiratory diseases were found to be higher in low socioeconomic position groups compared to high ones. The analyses by districts have shown several excess mortality/morbidity risks for residents in Tamburi (Tamburi, Isola, Porta Napoli and Lido Azzurro), Borgo, Paolo VI and the municipality of Statte. Conclusions: The results of this study showed a significant relationship between socioeconomic position and health status of people resident in Taranto. People living in the districts closest to the industrial zone have higher mortality/morbidity levels compared to the rest of the area also taking into account the socioeconomic position

The stability for the Cauchy problem for elliptic equations

We discuss the ill-posed Cauchy problem for elliptic equations, which is pervasive in inverse boundary value problems modeled by elliptic equations. We provide essentially optimal stability results, in wide generality and under substantially minimal assumptions. As a general scheme in our arguments, we show that all such stability results can be derived by the use of a single building brick, the three-spheres inequality.Comment: 57 pages, review articl

Cerebral plasticity in acute vestibular deficit

The aim of this study was to analyze the effect of acute vestibular deficit on the cerebral cortex and its correlation with clinical signs and symptoms. Eight right-handed patients affected by vestibular neuritis, a purely peripheral vestibular lesion, underwent two brain single photon emission computed tomography (SPECT) in 1 month. The first SPECT analysis revealed reduced blood flow in the temporal frontal area of the right hemisphere in seven of eight patients, independent of the right/left location of the lesion. The alteration was present always in the right, non-dominant hemisphere and was reversible in some patients 1 month after the onset, together with attenuation of signs and symptoms. It may be hypothesized that the transient reduction of cortical blood flow and subsequently of cortical activity in the non-dominant hemisphere, also the expression of cerebral plasticity, may serve as a defense mechanism aimed to attenuate the vertigo symptom

Probing the role of dynamical friction in shaping the BSS radial distribution. I - Semi-analytical models and preliminary N-body simulations

We present semi-analytical models and simplified $N$-body simulations with $10^4$ and $10^5$ particles aimed at probing the role of dynamical friction (DF) in determining the radial distribution of Blue Straggler Stars (BSSs) in globular clusters. The semi-analytical models show that DF (which is the only evolutionary mechanism at work) is responsible for the formation of a bimodal distribution with a dip progressively moving toward the external regions of the cluster. However, these models fail to reproduce the formation of the long-lived central peak observed in all dynamically evolved clusters. The results of $N$-body simulations confirm the formation of a sharp central peak, which remains as a stable feature over the time regardless of the initial concentration of the system. In spite of a noisy behavior, a bimodal distribution forms in many cases, with the size of the dip increasing as a function of time. In the most advanced stages the distribution becomes monotonic. These results are in agreement with the observations. Also the shape of the peak and the location of the minimum (which in most of the cases is within 10 core radii) turn out to be consistent with observational results. For a more detailed and close comparison with observations, including a proper calibration of the timescales of the dynamical processes driving the evolution of the BSS spatial distribution, more realistic simulations will be necessary.Comment: Accepted for publication by ApJ; 11 pages, 11 figure

Cortical metabolic arrangement during olfactory processing:proposal for a 18F-FDG PET/CT methodological approach

The aim of this article is to investigate the cortical metabolic arrangements in olfactory processing by using 18F fluorodeoxyglucose (FDG) positron emission tomography/computed tomography. Twenty-six normosmic individuals (14 women and 12 men; mean age 46.710 years) were exposed to a neutral olfactory condition (NC) and, after 1 month, to a pure olfactory condition (OC) in a relatively ecological environment, that is, outside the scanner. All the subjects were injected with 185-210 megabecquerel of 18F FDG during both stimulations. Statistical parametric mapping version 2 was used in order to assess differences between NC and OC. As a result, we found a significant higher glucose consumption during OC in the cuneus, lingual, and parahippocampal gyri, mainly in the left hemisphere. During NC, our results show a relative higher glucose metabolism in the left superior, inferior, middle, medial frontal, and orbital gyri as well as in the anterior cingulate cortex. The present investigation, performed with a widely available functional imaging clinical tool, may help to better understand the neural responses associated to olfactory processing in healthy individuals and in patients with olfactory disorders by acquiring data in an ecologic, noise-free, and resting condition in which possible cerebral activations related to unwanted attentional processes might be avoided

Recurrent Microinvasive Subungueal Squamous Cell Carcinoma in a HIV Patient: a Case of Good Response to Photodynamic Therapy.

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Cerebellar metabolic involvement and its correlations with clinical parameters in vestibular neuritis

Although vestibular neuritis (VN) cortical models are described in the literature, there is lack of knowledge regarding the exclusive cerebellar involvement. The aim of the present study was to analyze, by [18F] fluorodeoxyglucose-positron emission tomography (FDGPET)/ computer tomography, regional cerebellar FDG uptake in eight right-handed VN patients (five females; three males; mean age 48 ? 7 years) during the first few days (PET0) and after 1 month (PET1) since symptoms onset. At both phases, patients underwent otoneurological examination and filled in a battery of validated questionnaires. Twenty-six cerebellar volumes of interest (VOI) were identified by the automated anatomical labeling library and normalized to thalamus FDG-PET uptake. Mean intensity within VOIs was calculated in both phases and processed by within-subjects ANOVA. A significantly lower (

Variations of neck structures after supracricoid partial laryngectomy: a multislice computed tomography evaluation

Background: Surgery of laryngeal cancer used to profoundly alter the anatomy of the cervical region. Accurate anatomo-embryologic studies and repeated surgical trials allowed recognition of the cricoarytenoid complex as the smallest anatomofunctional unit able to maintain all the laryngeal functions. Objectives: The aim of this study was to determine whether significant variations of neck anatomical parameters exist after partial laryngectomy, and to analyze whether some of these parameters are associated with a positive functional outcome. Methods: Out of 48 patients treated with a surgical technique according to Mayer-Piquet (cricohyoidoepiglottopexy, CHEP) over a 6-year period, 18 patients were enrolled in the study. Patients were all males with a mean age of 60 years. Cervical structures and their relationships were measured by computed tomography, and the measurements before and after surgery were compared. Results: Our data showed that hyoid bone is modified, both in morphology and position during CHEP. More specifically the relation of the hyoid bone to other neck structures ( identified by the alpha-angle) is modified. The neolarynx and trachea undergo a caudocranial shift. All diameters of the cricoid cartilage remain unchanged after surgery. The position of the epiglottis after CHEP, in particular its relation with the arytenoid cartilage, is closely related to swallowing function outcome and recovery time. Conclusions: Our study showed that these structures, and more specifically the relations among them, undergo significant variations after CHEP. Our results identify some parameters, i.e. the alpha-angle, width of the hyoid bone and position of the epiglottis, that may predispose to a positive functional outcome after surgery